Electric-arc interrupter



(No Model.)

E. THOMSON.

ELECTRIC ARC INTERRUPTER.

No. 463,762. Patented Nov. 24, 1891.

M HHHHMMHWW ELII'IU THOMSON, OF SlVAllIPSOOTT, MASSACHUSETTS.

ELECTRlC-ARC INTERRUPTER.

SPECIFICATION forming part of Letters Patent No. 463,762, dated November 24, 1891.

Application filed December 15, 1890. Serial No. 374,696. (No model.)

To all whom it may concern:

Be it known that I, ELIHU THOMSON, a citizen of the. United States, residing at Swampscott, county of Essex, and State of Massachusetts, have invented a certain new and useful Improvement in Electric-Arc Interrupters, of which the following is a specification.

The present invention relates to electric switches and other devices at or by which an electric circuit is interruptedfor instance, lightning-arresters, fuses, &c.

Its object is to prevent the continuance of an are at the circuit-breaker and also to extinguish the arc effectually without the production of a flame between the parts which form the terminals or between which the are i is drawn.

The present invention is in some particulars similar to that described in Patent No.

321,464, granted to me July 7, 1885, in which a magnetic arrangement or an air-jet is used to disturb or blow out the are forming at a lightnin g-arrester. It, however, differs in this respect, that I now provide in addition to the ordinary arc-distorting arrangement a set of arc dividing or cooling plates,into which the arc or flame formed at the circuit-breaker is thrown forcibly, causing its immediate extinguishment; or, in other words,I quickly transfer the are as it forms to a set of separated and insulated conducting-plates, generally copper, which are placed near to each other opposite the point of the switch where the arc is liable to be produced. The fact that there are quite a number of plates into which this are is thrown and between which it is forced is sufficient cause for its extinguishment on account of the cooling effect of the plates and ent modified ways in which the invention may be applied.

To the switch-handle His attached the movable portion of the switch 0, by which contact is made when the switch is closed by hearing against or otherwise bridging the two strips (Z d, forming the fixed portion of the switch, the circuit being from one bindingpost, as A, to the other A through the switchcontacts. These parts are'mounted on a base B, of insulating material. By throwing the handle II, which is pivoted at a, to the left, as shown in dotted lines, the circuitis broken. If, however, a high potential exist upon the line, an are or flame might follow the opening of the switch. To avoid this-arcingI have provided in former patents a magnet whose poles e111- brace the switch-contacts and stand partlyover them, thereby causing the contacts to move in a magnetic field. This tends to distort outward from the poles any are or flame which is prod uced on opening the switch, and thereby limiis the duration of such are to a very small period, and at the same time causes a very quick disruption of the current. The current for operating the magnet is often in series with the line leading to the switch; but it may be energized in any other way, the only requirement being that it shall afford a suflicientlystrong magnetic field. In cases, however, in which the arc is so formed and driven forcibly out of position a considerable flash or disagreeable sputtering flame is produced, which it is desirable to avoid, and this I accomplish by my present invention, while at the same time the switch is opened with much less burning and destructive action than if the magnetic field alone be used.

I apply to the switch and in the magnetic field between the magnet poles a bundle of separated metal plates P P, mounted properly on insulating-supports and placed parallel one to the other in a series, whereby an arc can be driven by the magnet in between the plates and quickly extinguished. The disposition is more clearly shown in Fig. 3, where I it is seen that the plates P Pare set edgewise facing the switch, and are perforated so as to surround the contacts which meet to close the circuit. Hence the circuit will be broken in the body of the bundle of plates, and the are driven by the magnet M, whose poles overhang the switch outward into the air-spaces by which alone the plates are separated. The plates are preferablymade of coppera good conductor of heat-and will subdivide the heating effect, while at the same time the are or flame will be cut up into a number of smaller arcs, each one of which is immediately extinguished by the presence of such alarge cooling-surface and the existence of a comparatively large number of them in series. The disposition described in which the plates surround the circuit-breaker is not actually necessary, as the bundle might be simply placed above it, as in Fig. 3, where the contacts a 1), representing a switch,lightning-arrester, or other like device are seen separated by a space C1 and a jet of air delivered from nozzle J forces the are between the plates. Fig. 4 shows the fuse F shunting the parts a b, and the air-jet from J would then on the melting of the fuse force any are forming between a and Z; in between the plates P P, and thereby extinguish it. In Fig. 5 an air-jet is also shown as the arc-distorter, and the movable portion .C of the switch, when opened, controls a valve or cook in the pipe leading to J and turns on at the required moment the jet of air for forcing the arc in between the plates P P, placed beyond the switch-contacts.

This of course would save the air which might otherwise have to flow continually. The valve would always remain closed when the switch is closed and be opened the instant the switch is opened. This same effect may also be obtained with the magnet seen in Figs. 1 and 2. This is done by dividing the fixed portion of the switch into two portions cl d, which are, however, electrically connected through the coils of the electro-magnet M, as is represented by the black lines 0. When the switch is closed, as in the full-line position, the mag-' net will be shunted and out of circuit; but when the switch is opened the arrangement will be such as to throw the magnet at once into circuit. This can be readily done by extending the portion (1 overalittle beyond the end of portion (Z, where the switch makes the break; or, in other words, the switch-contact 0 leaves strip cl last, whereby the magnet is, as it were, forced into circuit at the moment of opening the switch, and remains in aslong as there is any arc-flow across the break.

WVhat I claim as new, and desire to secure by Letters Patent, is

1. The combination, with an electric circuit breaker, of an arc-distorter acting to drive the are out of position, and a bundle of insulated conducting-plates for receiving and extinguishing any are formed at the circuitbreaker, as set forth.

2. The combination, with an electric circuit breaker, of a bundle of insulated conducting-plates surrounding one or both of the contacts, and an arc-distorter acting to divert any are formed at the contacts to the plates, as set forth.

3. The combination, with a circuit-breaker, of a blow-out magnet thrown into circuit upon the opening of the main circuit, and the separated conducting-plates arranged between the poles of the magnet for receiving any are formed at ,the contacts.

4:- The combination,with an electric switch, of a blow-out magnet for extinguishing an arc thereat, and a circuit for energizing the magnet directly in or derived from the main circuit and controlled by the switch, the switchcontacts being so arranged as to complete a circuit through the magnet when thrown into a position rupturing the main circuit, as set forth.

In testimony whereof I have hereto set my hand this 11th day of December, 1890.

ELII-IU THOMSON.

W itn esses:

JOHN W. ,GIBBONEY, BENJAMIN B. HULL. 

